Hard ceramic materials are known and are used extensively in such applications as metal cutting and boring tools, metal drawing dies, wear-resistant machine parts and the like. It is also known that the service properties such as wear, high temperature and chemical resistance of such materials may be enhanced by the application of one or more thin coatings of, for example, metal carbides, metal nitrides, or ceramics. Great strides have been made in improved performance of these coated substrates, for example in machining applications, by refinement of the substrate compositions and by applying various combinations of superimposed layers of coating materials. However, increasingly stringent use conditions, for example use at high cutting speeds or in extremely high temperatures and/or corrosive environments, are placing increasing demands upon the performance of such materials.